Inlet Manifold.

[arjunior45]

which are the advantages - disadvantages for the following inlet manifolds?

A} Authentic one

B} from Lancia Delta Integrale

C} from Lancia Kappa

and

D} what do you think for one like these?

[AlfaJack]

Watching with interest.

Didn't Stuntz make his own? Not heard any progress for a while

[mindus]

A) as compared to B) or C) or D) - higher torque at low RPM
A) disadvantage - very very very heavy as compared to (C) kappa. don't have the scale, but OEM weights tons as compared to Kappa
A) the inner diameter of pipes (where it connects to the enginehead) is smaller as compared to C).
A) - it takes more space as compared to all other under the bonnet.

C) disadvantage - you'd probably need to modify OEM a fuel rail, but can not confirm this 100% yet..
D) the one in the first picture looks very nice...

which are the advantages - disadvantages for the following inlet manifolds?

A} Authentic one

B} from Lancia Delta Integrale

C} from Lancia Kappa

and

D} what do you think for one like these?

[arjunior45]

The first picture has 4 throttle as well as the inlet manifold {the part that goes to the engine head} from GrA Integrale / 155 GTA. Only the 'outer' part is 'handmade'.

[1NRO]

What kind of engine power and rpm are you looking to compare the suitability to? Different design trends depending on target.

I've recently been making one which is away getting it's final bit of main welding done, it'll come back more or less looking like the finished item minus the various sensor fittings and vac pipe connection which I don't know exactly where they will be until I'm a bit further into the build. A chopped up kappa manifold for the runners with a heavy duty pair of plenums welded on Anyway, here's some pictures, some which rely on tape and bluetack for picture purposes / fabrication :-)
http://i3.photobucket.com/albums/y85...tubes009-1.jpg
http://i3.photobucket.com/albums/y85...llmouth002.jpg
http://i3.photobucket.com/albums/y85...welding020.jpg
http://i3.photobucket.com/albums/y85...welding018.jpg
http://i3.photobucket.com/albums/y85...llmouth003.jpg
http://i3.photobucket.com/albums/y85...acement003.jpg

[jimnielsen]

I'd like to get a Kappa manifold too, on which to base a 'new' inlet manifold. Also - i'd like to try just a standard kappa manifold. It may well need a new fuel rail - but they are easy to make and access would be SO much better than the Q4 rail.

[1NRO]

Prestocar tried a standard Kappa manifold on an engine that had nearly 500bhp already and apparently gained 5% ish. The problem though with the kappa manifold is too long a runner for those kind of power levels and a too small plenum, still had improvments but not as much as it might have had if it wasn't designed for a low rpm target.

[AlfaJack]

What kind of engine power and rpm are you looking to compare the suitability to? Different design trends depending on target.

I've recently been making one which is away getting it's final bit of main welding done, it'll come back more or less looking like the finished item minus the various sensor fittings and vac pipe connection which I don't know exactly where they will be until I'm a bit further into the build. A chopped up kappa manifold for the runners with a heavy duty pair of plenums welded on Anyway, here's some pictures, some which rely on tape and bluetack for picture purposes / fabrication :-)
http://i3.photobucket.com/albums/y85...tubes009-1.jpg
http://i3.photobucket.com/albums/y85...llmouth002.jpg
http://i3.photobucket.com/albums/y85...welding020.jpg
http://i3.photobucket.com/albums/y85...welding018.jpg
http://i3.photobucket.com/albums/y85...llmouth003.jpg
http://i3.photobucket.com/albums/y85...acement003.jpg

Lovely work!

[arjunior45]

Prestocar tried a standard Kappa manifold on an engine that had nearly 500bhp already and apparently gained 5% ish. The problem though with the kappa manifold is too long a runner for those kind of power levels and a too small plenum, still had improvments but not as much as it might have had if it wasn't designed for a low rpm target.

well, let me ask you something.

I do care about torque and low – middle rpm and mostly about rev up the engine at those ‘low-middle’ rpm. I do not care that much for high rpm and ‘absolute’ power.

Will be better to have ‘long runs’ and ‘small plenum’?
With runs at the same length-size, does a smaller plenum have any improvement?

And what about the throttle size? A bigger one can make things worse?

[1NRO]

The 5% improvement was seen at high rpm rather than low.

The kappa manifold is designed for a standard level of power with the constraints of the engine it was to be fitted to in mind. So if you where to stick to a standard setup but fit a kappa manifold it's fair to say an improvement can be expected. The further you move away from a standard setup the less suitable it might prove to be.

Longer runners suit a lower rpm and shorter ones higher rpm. Big plenums aren't a problem with drivability, it's just a chamber that the engine is trying to drain. a big throttle can make drivability worse, most after market stuff has a less than nice linkage gearing / caming. The one I'm using is a nice progressive mechanism and not silly big. There are a few little tricks in the plenum that help with this too.

It's perfectly possible to have a very powerful turbo engine that has excellent low rpm performance. Just because you want to protect low rpm doesn't mean you can't have power to make your eyes water.

[arjunior45]

ok, thanks for the answer.
But, what about if there is no 'plenum' at all - like the first picture I've posted earlier? This should have a quicker responce to the throttles, don't you think?

[1NRO]

It has a plenum the first picture doesn't it?

Do the maths on how much volume of air a given turbo passes into the induction system at the edge of surge and you'll see that there is no shortage even at this nearly unstable level. It doesn't take a moment for the capacity to fill when the throttle cracks open, it's handy though for the engine to have a good gulp at the beginning.

How about lag? where does that come from?

[arjunior45]

yes, the first picture has a plenum but this one is 'before' the 4 throttles! So it has pressurized air in its space {from 1500 rpm and upwards - at idle has 0 bar but in any case no vacuum} and this pressurized air, as soon as the throttles open, goes directly to the inlet valves - no need to fill any space {small or bigger}. If I'm not mistaken, with this set up throttle response must be quicker.

In the oem set up, the plenum is between throttle and inlet manifold and it's a space with vacuum up to 1500rpm {more or less}. So when throttle opens there is the capacity of the plenum that 'must' be filled. Even if it takes a moment.

If the above are wrong please forgive my ignorance.
You see, I have no experience with turbo cars and I would like to understand the way it works. And believe that 'inlet' set up should be as important as the 'exhaust' set up.

I have something in mind and I'd like to have experts opinion.
I'm planing to go for :
a} short 'runs' {if this is correct - from the engine head to the throttles}
b} 4 throttles
and
c} a small 'plenum' connecting the throttle bodies to the intake 'sleeve'.
The only thing that troubles me is the position and the connection of the ICV valve to the trottle bodies.


And what about lag? I really do not know where does it come from and if the inlet setup influence that much - regardless the turbine.

[1NRO]

Nick,

I personally don't see much worth in ITB's, ok there might be a fractionally quicker response but it's tiny and the benefits end there whilst the normal method of throttle before plenum allows some good work to be done with tuned runner lengths which won't work with ITB's. The main reason I didn't continue with ITB's is the unevenness of the air flow into the throttles, with the air sweeping round and into the plenum there is a bias towards some cylinders at the expense of starving others. It's possible to work through some of the problems they bring but there's just too much potential for inferior results and their complex nature makes them liable to cause problems in use (lots of areas for boost leaks for instance, four throttle spindles for a start and a total of 9 gaskets after the plenum not to mention the throttle linkage) I've spent a lot of time looking at them and for me the simple method is best but feel free to give it a go, it'll look bling if nothing else.

I mention lag as i think maybe you are looking at trying to reduce it in the wrong areas. As I said work out the amount of air involved in a turbo application and you will soon see that we aren't "waiting" for air to be supplied. Compare the amount the turbo supplies at a given rpm to the amount the engine consumes at that same rpm.

Nik

[arjunior45]

Thanks for the reply Nik.
I'll sleep over and I'll give it a try as soon as I'll find a 'plenum' that can couple with the 4 throttle bodies {I have already as spare parts}.

[kepsus]

the xxx pic, is a inlet manifold from a 20vt, and they are as standard pretty good. I did also put larger trottle on it and that was in fact not the best thing to do on a road car, it is a kind of on and off..

[arjunior45]

this "a kind of on and off.." rings a bell to me.
Something like 'kenneth' maybe?

[kepsus]

correct that's me :-)

i have just got a a 70mm throttle and would try that instead of the 90

[arjunior45]

waiting for your comments.

[kepsus]

sure but do not think i would have to do if before around monday, i have forgot my laptop on job, and would like to hvae it on the car to see how it behave.

[1NRO]

Thanks for the reply Nik.
I'll sleep over and I'll give it a try as soon as I'll find a 'plenum' that can couple with the 4 throttle bodies {I have already as spare parts}.

Jenvey do a modular plenum that could likely be fitted, pretty good bit of kit for a normal bhp level. Pretty pricey at over ?500

Just looking through some of the stuff I have on ITB's and thought maybe you'd like a bit of full on bling, most excellent and mucho expensive.

[1NRO]

I like this one too, over ?600's worth of wiggins clamp before you even start making the rest but it is very nice.

[kepsus]

what is that from ?? integrale or, and for road use or only "402 meters" ?

[1NRO]

Second one? Can't remember what motor it was on but not one we have. Looks to me to be an all out, all rpm, top of the range, well designed, tractable beauty. Pretty much excellent for everything. I can only think of one feature that i can't see it has that I suspect it might have that I'd have on top of what you see there if money was no object.

[arjunior45]

The first one reminds me of a N/A F1 setup and involves NOs or H2O? NOT road use, that's for sure! But where the TPS goes?

Second one has a very interesting plenum!!!